UC Santa Barbara Geography / News & Events / Department News

March 05, 2013 - Toxic Zombie Mice versus Guam’s Brown Tree Snakes

“In what is likely to be remembered as one of the strangest pest control policies ever pursued, the U.S. territory of Guam has decided to combat the island’s ongoing snake infestation by parachuting painkiller-laced dead baby mice into the jungle canopy. For over 60 years, officials have been waging war against the brown tree snake, an invasive species that has killed off much of Guam’s native bird population, and which some experts fear may spread to Hawaii.

If all goes according to plan, infant mice corpses, wearing small parachutes and laced with the pain reliever acetaminophen, will be flung from helicopters flying over the jungle. Acetaminophen is deadly to the snakes. Officials hope that the rodent paratroopers will then become entangled in the foliage where the overpopulated reptiles will find and devour them. The success of the strategy hinges on two key facts about the brown tree snake: that it will eat prey that is already dead and that the species is lethally sensitive to acetaminophen.

Aside from decimating numerous native bird species, the brown tree snake has also proven to be a nuisance to the humans living on Guam. The reptiles, which can grow up to 10 feet in length, commonly slither up utility poles, causing occasional power outages. Snakebites are also not uncommon, though the bites are rarely fatal to people.

Reports of the Department of Agriculture policy have been met with howls of protest from the animal rights group, People for the Ethical Treatment of Animals (PETA), which calls the campaign a ‘clumsy, dangerous massacre.’ ‘For reptiles, death could take days or even weeks,’ says Martin Mersereau, a spokesperson for the group. ‘No animal should be forced to endure cruel death.’ The airdrop is slated to begin in April or May” (www.earthweek: "Dead Mouse Paratroopers to Combat Guam Snakes"; March 1, 2013).

Click here for an in-depth audio discussion regarding the plan to drop poisoned mice from helicopters to control the invasive brown tree snake in Guam. The presenter is Heather Jarvis of ABC Radio Australia, and the speaker is Daniel Vice, the Assistant State Director of the US Department of Agriculture's Wildlife Services in Hawaii, Guam, and the Pacific Islands.

The brown tree snake (Boiga irregularis) is an arboreal rear-fanged colubrid snake native to eastern and northern coastal Australia, Papua New Guinea, and a large number of islands in northwestern Melanesia. This snake is infamous for being an invasive species responsible for devastating the majority of the native bird population in Guam (Wikipedia: Brown tree snake)

A helicopter crewmember drops dead mice laced with pain reliever over a Guam Naval base in a test to see if the parachute system works. The miniature parachutes consist of two bits of cardboard linked by a long ribbon of paper; hopefully, most of the mice will get entangled in the tree canopies where the snakes are, rather than falling to the forest floor where they could be eaten by other native species. Some of the mice are planted with radio transmitters (www.earthweek; photo: Peter Savarie - U.S. Geological Survey)